It is common practice to add structures to the cargo bed of a pickup truck for a variety of purposes. The basic elements of such structures are usually a pair of rails which attach to the tops of the walls of the cargo bed above the wheel wells. Each of the rails may include a variety of attachment points for use in securing loads, covers, tool boxes, etc. However, there are limitations due to the need for secure connection and also because the side walls vary in shape and they may also diverge slightly to be wider apart adjacent the cab of the truck.
It is an object of the present invention to provide an improved attachment system for the cargo bed of pickup trucks which will provide adequate strength and facilitate the attachment of accessories such as covers, tool boxes, etc.